Communication systems comprising electromagnetic transponders are more and more frequent, particularly since the development of near-field communication technologies according to ISO standard 14493 or the NFC forum.
Such systems use a radio frequency electromagnetic field emitted by a device (terminal or reader) to communicate with another device (card).
To optimize the quality of the communication, the resonance frequency of an oscillating circuit of the device detecting a field is generally adjusted (tuned) due to capacitive and/or resistive elements having settable values.